Initial Cassini Magnetometer Observations of the neutral sheet of Titan's magnetic tail

LAW, A. L.; DOUGHERTY, M. K.; MUELLER-WODARG, I. C. F.; BERTUCCI, C. L.; NEUBAUER, F. M.; ARRIDGE, C. S.

Congreso; American Astronomical Society, DPS meeting #37; 2005

Titan is the largest moon of Saturn and the only moon in the solar system known to have a substantial atmosphere. There is no evidence of Titan having a significant intrinsic magnetic field, but its atmosphere does interact with its plasma environment (usually Saturn's magnetosphere). This interaction results in the magnetic field lines being draped around Titan, forming a magnetic tail. An important feature of this magnetic tail is the current carrying neutral sheet, which separates the Northern and Southern tail lobes. Cassini's first three close flybys of Titan were all at the same orbital position of 10.5 Saturnian Local Time (SLT) and each time the spacecraft flew through the neutral sheet plane. The next two flybys observed Titan close to dawn SLT, where the incident plasma encounters the weaker nightside ionosphere, again, Cassini flew through the plane of the neutral sheet. All of these encounters were within Saturn's magnetosphere. In this work we characterise Titan's neutral sheet as seen by the Cassini magnetcmeter (MAG) and other Cassini plasma instruments. We comment on its orientation with respect to the upstream magnetic field and we study its magnetic structure in order to have an estimate of the amount of current flowing across this boundary. The implications for the physics of the structure of the whole magnetic tail will also be discussed.